Just getting stronger especially with single leg exercises like heavy step-ups, lunges, bulgarian split squats etc. This has really helped me still be able to jump high off of one leg and dunk during games even though I've put on 30lbs since I played competitive basketball in high school. If anything when I'm in jumping shape, I'm jumping higher now than I was then. I will say though that I have been always trying to jump high off of one leg since I was like 10 years old so it comes pretty naturally to me.
